I was playing on SS4 a few minutes ago and this happened:
Pretty common problem for me. Since my iphone 5c up to my iphone 8. If you flip your phone rotation and back, it usually corrects itself.
If what jemnidad said doesnt work, then try double pressing the home button and then tapping back onto the app’s tab. thats what i do on my iphone 5.
This happens to me as well.
The chat is partially off-screen.
I know, I just decided to joke around.
And somehow when I was going to delete it I must had done something else and forgotten about it. I retracted my comment now.